Groupon's top daily deals rival in free fall

comScore estimates LivingSocial, once viewed as a major threat to Groupon's (GRPN-3.2%) daily deals hegemony, saw a 42% Y/Y drop in U.S. PC unique visitors in September to 4.6M, and a 28% drop in mobile uniques to 7.7M. By contrast, comScore thinks Groupon's U.S. PC uniques fell only 8% to 12M, and that its mobile uniques soared 66% to 33M.

LivingSocial doesn't deny it has seen a traffic drop; the company partly attributes the decline to a well-publicized hacking incident, and lower marketing spend on certain daily deals program as it tries to follow Groupon's lead in offering a "marketplace" of longer-term deals.

In its Q3 10-Q, Amazon, which owns 29% of LivingSocial, reported the company had revenue of $384M (-1% Y/Y) over the first nine months of 2013, and a net loss of $107M. LivingSocial has been cutting headcount in an effort to pare its losses.